A rapid development of Mobile Internet, Internet of Things and other service applications has become a main driving force for the development of the fifth generation mobile communication technology (5G). There is an urgent demand for the 5G to have an access rate comparable to optical fibers, connectivity of 100 billion devices, perfect real-time experience, and wireless broadband access at all times and places. In addition, energy efficiency, spectral efficiency and peak rate and other important indicators also need to be considered in a 5G system design. The IMT-2020 (5G) Promotion Group for promoting the development of 5G technology is established in China in 2013. According to the overall situation in the world, it is estimated that 5G vision, key capability needs and spectrum plan will be formed in 2015; 5G standardization work will be started thereafter and 5G will be put into commercial use after 2020. In terms of international standards, the LTE-Advanced technical standards are mainly formulated by the 3rd Generation Partnership Project (3GPP) International Organization for Standardization. The industry initially believes that research on 5G standards will be started in 3GPP Release 14 (R14) (expected in 2016).
In future mobile network applications, the demand for traffic, the number of terminals and the types of terminals will all show an explosive growth trend. As one of 5G's important scenes and technologies, Machine Type Communication (MTC) is receiving more and more attention. In general, there are four major needs for MTC: massive connection, low power consumption, low delay and high reliability. Massive connection is reflected in that the number of MTC devices is currently more than 10 times the number of human-to-human communication terminals. Low energy consumption is reflected in that the significance of energy saving is extraordinary because of a large number of MTC devices. Low latency and high reliability are reflected in that MTC devices have an end-to-end delay of 1 ms or shorter. MTC devices often need to transmit super real-time service data, so that a data processing center can timely analyze and process the service data and make corresponding actions. Thus research on super real-time services and delays will be an important technical point in the MTC research process.
In a related Long Term Evolution (LTE) system, a random access process is triggered by three modes: mode 1: triggered by a Physical Downlink Control Channel (PDCCH); mode 2: triggered by a Media Access Control (MAC) layer; and mode 3: triggered by an upper layer. In mode 1, when downlink data arrives, if the user is in a connected state and already in an asynchronous state (out-of-synchronization), the user is triggered to initiate a radio resource control (RRC) reconnection process; and if the user is in an idle state, the user is triggered to initiate an initial random access process. In mode 2, when the user needs to send uplink data, but the user is out of synchronization or has no Physical Uplink Control Channel (PUCCH) resource required for sending a scheduling request (SR), the user is triggered to initiate an RRC connection reconfiguration process. In mode 3, the random access process triggered by the upper layer includes initial random access, RRC connection reestablishment and handover.
For a user equipment having a super real-time service, if data transmission and signaling interaction can be implemented by utilizing a resource whose transmission time interval (TTI) is less than 1 ms (i.e., a short TTI), then a transmission delay of the user data and a delay in signaling interaction can be effectively reduced. However, the related art does not provide the following solution: in the random access process, a base station is triggered to allocate a short TTI resource to a user equipment having the super real-time service, and the base station performs signaling interaction with the user equipment by utilizing the short TTI resource.